鈥淭he current recycling techniques for plastic produce products of inferior quality. That is why I am working on new ways of chemical recycling.鈥�
Research focus: chemical recycling, upcycling, mechano-catalysis
Watch Ina Vollmer's lecture about the most recent research of her group .
The majority of plastic waste is landfilled, burned or leaks to the environment. Unfortunately, only 12 % (by weight) is recycled globally, mainly because the predominantly applied recycling technique of melting and re-extrusion produces a lower quality plastic. Therefore, chemical depolymerization of plastic has been studied to produce monomers which can be used to make high-quality plastic again. For polyolefins, however, only a very mixed, low value hydrocarbon stream was obtained thus far.4 This is because thermal cracking of the strong polyolefin bonds evokes random bond scission, uncontrolled further reaction and thus the formation of various products besides monomers.
My expertise is in mechano-chemistry1 and mechano-catalysis2-4, chemical recycling of plastics,5-9 and heterogenous catalysis8-10 as well as polymer chemistry and radical analytics. I teach polymer chemistry and electron spin resonance spectroscopy.
The research of the plastic recycling team focusses on developing pathways for the low temperature selective chemical recycling of plastic waste to chemical building blocks like aromatics,6, 7 carboxylic acids9 and monomers1-3. I am especially interested in using mechano-catalysis to drive the depolymerization and cracking reactions of polyolefins. Mechano-chemistry is a rather less developed field of chemistry where reactions are driven not by thermal energy, electrons or photons but rather by mechanical strain, which can lower the activation energy needed to be overcome for bond cleavage. This strain can, for example, be applied in a ball mill.
We developed a surface activated mechano-catalyst (SAM cat), which we patented.2-3 Instead of adding catalyst as powder to the ball mill, we functionalize the grinding spheres directly. This significantly improves performance. The catalyst is placed right where the energy input into the system is the highest, at the impact point of the spheres. In addition, it avoids difficulties in bringing the powder catalyst, polymer and grinding spheres together at the same location at the same time.
Open Science:
I lead the activities towards digitalization in the group according to the principle of findable, accessible, interoperable and reusable data (FAIR). We have set up a procedure for data storage on the Yoda server of UU that is then published openly via a doi link. We have also set up a group wiki and electronic lab journals and are currently setting up a server infrastructure to automatically back up all raw measurement data from over 40 lab instruments.
References:
(1) Aydonat, S., Hergesell, A. H., Seitzinger, C. L., Lennarz, R., Chang, G., Sievers, C., Meisner, J., Vollmer, I., & G枚stl, R., Leveraging mechanochemistry for sustainable polymer degradation. Polymer Journal, 2024, 56(4), 249鈥�268.
(2) Hergesell, A. H., Baarslag, R. J., Seitzinger, C. L., Meena, R., Schara, P., Tomovic, 沤., Li, G., Weckhuysen, B. M., & Vollmer, I. (2024). Surface-Activated Mechano-Catalysis for Ambient Conversion of Plastic Waste. Journal of the American Chemical Society, 146(38), 26139鈥�26147.
(3) Vollmer, I., Hergesell, A.H., Seitzinger, C.L, patent application, EP24170863.5
(4) Vollmer, I., Hergesell, A.H., Weckhuysen, B.M., patent application,
(5) Vollmer, I., Jenks, M.J.F., Roelands, M.C.P, White, R.J., van Harmelen, T., de Wild, P., van der Laan, G.P., Meirer, F., Keurentjes, J.T.F., Weckhuysen, B.M., Beyond Mechanical Recycling: Giving New Life to Plastic Waste. Angew. Chem. Int. Ed. 2020, 59 (36), 15402鈥�15423,
(6) Vollmer, I., Jenks, M. J. F., Gonz谩lez, R. M., Meirer, F. & Weckhuysen, B. M., Plastic Waste Conversion over a Refinery Waste Catalyst. Angew. Chem. Int. Ed., 2021, 60 (29), 16101鈥�16108,
(7) Rejman, S., Vollmer, I., Werny, M., Meirer, F., Vogt, E., Weckhuysen, B. M., Transport Limitations in Polyolefin Cracking at the Single Particle Level, Chem. Sci., 2023, 14(37) 10068-10080, (data available at: )
(8) Thevenon, A., Vollmer, I., Towards a Cradle-to-Cradle Lifecycle for Polyethylene, Angew. Chem. Int. Ed., 2023, 62 (3), e202216163,
(9) Smak, T. J., de Peinder, P., van der Waal, J. C., Altink, R., Vollmer, I., & Weckhuysen, B. M., Oxidative Conversion of Polyethylene Towards Di-Carboxylic Acids: A Multi-Analytical Approach. ChemSusChem, 2023, 17 (7), e202301198.
(10) Vollmer, I., Kosinov, N. Sz茅cs茅nyi, 脕, Li, G., Yarulina, I, Abou-Hamad, E., Gurinov, A., Ould-Chikh, S., Aguilar-Tapia, A. Hazemann, J.L., Pidko, E., Hensen, E. J. M., Kapteijn, F., Gascon, J., A site-sensitive quasi in-situ strategy to characterize Mo/HZSM-5 during activation, J. Catal. 2019, 370, 321-331, doi.org/10.1016/j.jcat.2019.01.013
(11) Vollmer, I., van der Linden, B., Ould-Chikh, S., Aguilar-Tapia, A., Yarulina, I., Abou-Hamad, E., Sneider, Y.G., Olivos Suarez, A.I., Hazemann, J.L., Kapteijn, F., Gascon, J., On the dynamic nature of Mo sites for methane dehydroaromatization, Chem. Sci. 2018, 9 (21), 4801鈥�4807,
(12) Vollmer, I., Ould-Chikh, S., Aguilar-Tapia, A., Li, G., Pidko, E., Hazemann, J.L., Kapteijn, F., Gascon, J., Activity Descriptors Derived from Comparison of Mo and Fe as Active Metal for Methane Conversion to Aromatics. J. Am. Chem. Soc. 2019, 141 (47), 18814鈥�18824,
(13) Vollmer, I., Abou-Hamad, E., Gascon, J., Kapteijn, F., Aromatization of ethylene鈥搈ain intermediate for MDA?, ChemCatChem 2020, 12 (2), 544-549,